Friction device.



W. W. WHITUOMB.

PRIGTION DEVICE.

APPLICATION FILED JULY 11,1913.

Patented Dec. 30, 1913.

UNITED STATES PA n retort,

WILLIAM WIRT WHITGOMB, OF BROOKLINE, MASSACHUSETTS.

FRICTION DEVICE.

Specification of Letters Patent.

Application filed July 11, 1913.

.atcnted11120.3(), l 5913. Serial No. 778,473.

To all whom it may concern:

Be it known that I, WiLLiAM W in'r VVilrrcome, a citizen of the United States, residing in Brookline, county of Norfolk, and State of Massachusetts, have invented an Improvement in Friction Devices, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to a friction device and is herein shown as a brake-shoe or clutchingmember.

The invention has for its object to provide a friction device of maximum durability and braking or clutching efiiciencv at a minimum cost, and one which is especially adapted for use in places where it is subjected to severe usage, as, for instance, on railway cars. To thisend, the friction device is provided with preferably a fplurality of sockets, in which are placed ho ow or tubular gripping members of resilient material, preferably cork in its natural state, and which are retained in fill the center tion on the line 6.(3, Fig. 5-.

said sockets by means of center plugs of relatively rigid or harder material, which bore of the gripping members and force or expand the same outwardly into firm contact with the walls of the said sockets. The expanding plugs may be of metallic material, such as steel, 0- they may be of non-metallic material of suflicient rigidity or hardiness, such as porcelain, wood or like material, and said plugs have their outer surface substantially flush with the outer surface of the friction member and of the resilient gripping members, so as to confine the gripping member between the rigidor hard wearing surfaces, whereby the gripping member is maintained in its most etl'ective condition with its outer or contact-- g'ing surfaccprotected against disintegration, tearing or rupture usage.

under conditions of severe These and other features of this invention will be pointed out in the claims at the end of this specification.

Figure 1 represents in elevation one form of brake-shoe embodying this invention. Fig. 2, a section on the line 2-2, l ig. 1. Fig. 3, a section of the shoe shown in Fig. 1 with the plug member ren'ioved. F ig. 4, a detail of one form of plug member. Fig. 5, an elevation bfoif" rm of clutch member embodying the i'nve on, and Fig. 6, a seclteferring to the drawings, (t represents a friction device in the form of a brake shoe, such as is now commonly employed on steam railroads. The brake shoe a is provided with a plurality of sockets Z) in its body portion 0, which extends rearwardly from the front or contacting face (Z thereof, and which receive within them gripping members 0 of resilient material, preferably cork in its natural state. The gripping members 0 are provided with a central bore or opening f for the reception of center plugs or expanding members 9, which are of relatively. rigid or hard materia],'such as steel, porcelaimwood or the like. In the'present instance, the plug member g is shown separate from the brake-shoe or frictioirdevice a and is provided at its inner end with a. conical head 10, which forms an annular shoulder 12, and the socket b in the brake-shoe is provided with a bottom wall 141- and with a central concavity 15.

The tubular cork member 0 is inserted freely into the socket b and rests against the bottom 14 thereof and the plug member whichis made of larger diameter than the bore f of the cork member, s then forced through said bore until the head. 10 passes into the concavity 15 and the outer end of the plug member is flush or substantially flush with the outer or contacting face 03 of the brake-shoe, as represented in Fig. 2. \Vhen the plug member 9 is forced into the bore ofthe cork member 0, it expands the latter from within the same and forces the outer surface into firm contact with the walls of the socket and further compresses the cork between two rigid or hard wearing surfaces, with the result that the cork is firmly held under compression in its .sockct'and the outer-surface of the cork is protected from a tearing or disintegrating action when the shoe iscugaged with the revolving body with which it cooperates. In this manner, the life of the cork member is materially prolonged and the etliciency of the brake-shoc especially for railway service is greatly increased. F urthcrmore, the diameter of the sockets and of the cork members may be greatly increased, and a greater area of cork gripping surface ob tained at less cost, than can be obtained with solid corks, as in. practice it has been demonstrated that when solid corks are used, the best results are obtained with corks inserted into sockets tlntee-quarters of an m I wease inch 'in diameter, Whereas in the present case, the sockets can be made as large as one and one-half inches in diameter and the corks provided with a center bore of onehalf inch, and the plug member a diameter of seven-eighths or an inch. In this case, the area of the gripping member is materially increased, While at the same time, it is protected and preserved in its most efficient condition by the Wearing surfaces between which it is confined.

Vi hile the invention is especially applicable to a brakeshoe for railway uses, it is not desired. to limit the invention in this respect, as the invention may be embodied in other forms of friction devices, and in the present instance, I have illustrated it in Figs. and (3, as embodied in a clutch member in the form of adisk 20.

In the prescnt'instance, I have shown one form of plug member, which. is separate from the body portion of the socket memher, but it may be integral therewifi, and suitably shaped to effect the expansion of the cork, when the latter is forced into its socket.

Claims 1. A friction device of the character scribed, comprising a body portion prov d with a socket, a gripping member of re 1 ent material heated in said socket and provided with a bore whose walls are normally sqiarated, and a ping member of larger diameter than said bore and extended into the latter to enlarge the said hortand exi pand the said gripping member and form a l Wearing surface Within the latter, substantially as described.

A friction device of the character described, comprising a body portion provided 'With a socket, a gripping member of cork located in said socket with its outer surface substantially flush with the surface of said body portion and provided with a substantially' centralbore Whose Walls are normally separated, and a plug member of rigid. material of la=' :;er diameter than said here and extended into the latter to enlarge the said bore and with its outer surface snhstantialiy flash with the outer surface of said gripping; member, substantially as described. 4

it. friction device of the character described, comprising body portion provided with a socket, a gripping member of resilient material located in said socket and having an opening a'hoee Walls are normally separated, and a ping member located in said socket with its surface substan- I -and extended. into the to enlarge said opening the; member into firm 2e said body portion, sil ribed. V

roof, 1 have signed m.

in the presence moment Wi I u}? in testimony n name to this specincation of two snhserihik is' ii iii/ii ii i'tncs as:

irilh'the outer surface of said- 

